Thermal management system of electric vehicle and control method

Abstract

The invention relates to the technical field of thermal management, and provides a thermal management system of an electric vehicle and a control method.The system comprises a motor water cooling loop, a battery water cooling loop, an air conditioner loop and a third branch, and in the motor water cooling loop, a radiator, a motor cooling water pump and a driving motor are sequentially connected in series; the battery water-cooling loop comprises a battery pack and a circuit connected in parallel with the battery pack and formed by connecting a battery cooler and a battery water pump in series, and two ends of the battery pack are connected in parallel to the input end of the motor cooling water pump and one end of the driving motor far away from high voltage all-in-one through water valves; the air conditioning loop comprises a loop for heat exchange; and the third branch is used for inputting the cooling liquid output by the indoor heat exchanger into the battery cooler, performing heat exchange with the cooling liquid in the battery water-cooling loop and then inputting the cooling liquid back to the air-conditioning loop. The system can balance the heat requirements of components, reduce energy consumption, improve the battery performance, improve the driving comfort and improve the endurance mileage of the whole vehicle.

Description

Technical Field

[0001] The present disclosure belongs to the technical field of thermal management, and particularly relates to a thermal management system and a control method for an electric vehicle. Background Art

[0002] With the rapid development of the global new energy vehicle industry, the market ownership of pure electric vehicle models has been increasing year by year; however, the problem of the driving range of electric vehicles has always been the core pain point that users are concerned about. Especially in low-temperature environments, the battery performance decays significantly. At the same time, the energy consumption ratio of the on-vehicle thermal management system remains high, becoming an important factor affecting the driving range of the whole vehicle.

[0003] An efficient thermal management system not only needs to ensure that core components such as batteries and motors operate at appropriate temperatures to improve their performance and lifespan, but also needs to take into account the ride comfort. The existing technologies cannot well balance the thermal requirements of multiple components and reduce the system energy consumption. Summary of the Invention

[0004] To solve the above problems, the present disclosure provides a thermal management system and a control method for an electric vehicle, which adopt a multi-loop coupling strategy, can balance the thermal requirements of components, reduce energy consumption, and improve battery performance, ride comfort and the driving range of the whole vehicle.

[0005] The following are the technical details of the present disclosure:

[0006] A thermal management system for an electric vehicle includes a motor water cooling loop, a battery water cooling loop, an air conditioning loop and a third branch;

[0007] The motor water cooling loop includes a radiator 1.1, a motor cooling water pump 1.4 and a drive motor 1.6 connected in series in sequence;

[0008] The battery water cooling loop includes a battery pack 2.1 and a first cooling line for cooling the battery pack 2.1; the first cooling line includes a battery cooler 2.4 and a battery water pump 2.3 connected in series; the battery pack 2.1 is connected in parallel with both ends of the radiator 1.1 through a water valve;

[0009] The air conditioning loop includes: a compressor 4.1, an indoor heat exchanger 4.2, a first water-cooled condensation stop valve 4.6.2, a water-cooled condensation electronic expansion valve 4.6.3 and a water-cooled condenser 3.1 connected in series in sequence; two branches are led out from one end of the water-cooled condenser 3.1 far away from the water-cooled condensation electronic expansion valve 4.6.3; wherein the first branch is used to input the coolant back to the compressor 4.1, and the second branch is used to input the coolant output from the water-cooled condenser 3.1 to the indoor evaporator 4.4 and then return to the compressor 4.1;

[0010] The third branch is used to input the coolant output by the indoor heat exchanger 4.2 into the battery cooler 2.4 for heat exchange with the coolant in the battery water cooling circuit, and then input it back into the air conditioning circuit.

[0011] Further,

[0012] The first branch includes a second water-cooled condensation cut-off valve 4.6.7 and a gas-liquid separation tank 4.5 connected in series, and the output end of the gas-liquid separation tank 4.5 is connected to the input end of the compressor 4.1;

[0013] The second branch includes an evaporator electronic expansion valve 4.6.1 and an indoor evaporator 4.4 connected in series, and the output end of the indoor evaporator 4.4 is connected to the input end of the gas-liquid separation tank 4.5.

[0014] Further,

[0015] The third branch includes:

[0016] A first battery heating cut-off valve 4.6.4 and a battery cooling electronic expansion valve 4.6.5 connected in series in sequence;

[0017] One end of the first battery heating cut-off valve 4.6.4 far from the battery cooling electronic expansion valve 4.6.5 is connected to the output end of the indoor heat exchanger 4.2;

[0018] One end of the battery cooling electronic expansion valve 4.6.5 far from the first battery heating cut-off valve 4.6.4 is connected to one end of the water-cooled condensation electronic expansion valve 4.6.3 far from the water-cooled condenser 3.1 after passing through the battery cooler 2.4.

[0019] Further,

[0020] It further includes a fourth branch, which is used to input the coolant output by the water-cooled condenser 3.1 into the battery cooler 2.4 for heat exchange with the coolant in the battery water cooling circuit, and then input it back into the air conditioning circuit. It includes:

[0021] A third water-cooled condensation cut-off valve 4.6.8, one end of which is connected to one end of the water-cooled condenser 3.1 far from the water-cooled condensation electronic expansion valve 4.6.3, and the other end is connected to one end of the battery cooling electronic expansion valve 4.6.5 far from the battery cooler 2.4;

[0022] A first battery cooling cut-off valve 4.6.6, one end of which is connected to one end of the battery cooler 2.4 far from the third water-cooled condensation cut-off valve 4.6.8, and the other end is connected to the input end of the connected gas-liquid separation tank 4.5.

[0023] Further,

[0024] One end of the water-cooled condenser 3.1 is also connected to one end of the radiator 1.1 after passing through the water-cooled condensate pump 3.4;

[0025] The other end of the water-cooled condenser 3.1 is connected to the other end of the radiator 1.1.

[0026] Furthermore,

[0027] The motor water-cooling circuit further includes:

[0028] A water-cooled condensate three-way valve 1.3, two of its ports are connected to the radiator 1.1 and the motor cooling water pump 1.4, and the third port is connected to the water inlet of the water-cooled condensate pump 3.4.

[0029] Furthermore,

[0030] It further includes:

[0031] A coolant storage tank 3.5, used for exhausting air from the coolant circuit and replenishing the cooling medium; its output end is connected to the water inlets of the motor cooling water pump 1.4, the battery water pump 2.3, and the water-cooled condensate pump 3.4.

[0032] A control method for the thermal management system of the electric vehicle described above, including:

[0033] When there is a passive cooling demand for the battery in the thermal management system:

[0034] Open the radiator 1.1 and the battery water pump 2.3, and conduct the water valve so that the coolant output from the radiator 1.1 flows through the battery pack 2.1 and then is transmitted back to the input end of the radiator 1.1.

[0035] Furthermore,

[0036] When there is a passive heating demand for the battery in the thermal management system and a passive cooling demand for the motor:

[0037] Open the motor cooling water pump 1.4 and the battery water pump 2.3;

[0038] Conduct the water valve so that the coolant passing through the motor flows through the battery pack 2.1 and then is transmitted back to the water inlet of the motor cooling water pump 1.4.

[0039] Furthermore,

[0040] When there is an active cooling demand for the battery in the thermal management system and a refrigeration demand for the air-conditioning circuit:

[0041] Open the battery water pump 2.3 and the battery cooler 2.4;

[0042] Open the compressor 4.1, the first water-cooled condensate stop valve 4.6.2, and the indoor evaporator 4.4;

[0043] The coolant output from the water-cooled condenser 3.1 is input into the battery cooler 2.4 through the fourth branch, where it exchanges heat with the coolant in the battery water-cooling loop and then is input back into the air-conditioning loop.

[0044] Furthermore,

[0045] When there is an active heating demand in the battery loop and a heating demand in the air-conditioning loop in the thermal management system:

[0046] Turn on the battery water pump 2.3 and the battery cooler 2.4;

[0047] Turn on the compressor 4.1 and the indoor heat exchanger 4.2;

[0048] And use the third branch to input the coolant output from the indoor heat exchanger 4.2 into the battery cooler 2.4, where it exchanges heat with the coolant in the battery water-cooling loop and then is input to the end of the water-cooled condensing electronic expansion valve 4.6.3 far from the water-cooled condenser 3.1.

[0049] Furthermore,

[0050] When there is an active cooling demand in the battery loop and a heating demand in the air-conditioning loop in the thermal management system:

[0051] Turn on the battery water pump 2.3 and the battery cooler 2.4;

[0052] Turn on the compressor 4.1, the indoor heat exchanger 4.2 and the first water-cooled condensing stop valve 4.6.2;

[0053] Use the third branch to input the coolant output from the indoor heat exchanger 4.2 into the battery cooler 2.4, where it exchanges heat with the coolant in the battery water-cooling loop and then is input back into the air-conditioning loop.

[0054] Compared with the prior art, the present disclosure has the following advantages:

[0055] In the motor water-cooling loop of the present disclosure, the coolant is pushed by the motor cooling water pump to circulate among the heat dissipation module, the high-voltage multi-in-one unit and the drive motor, taking away heat and ensuring the stable operation of the motor and related components;

[0056] In the battery water-cooling loop, the battery pack is in parallel with the circuit including the battery cooler and the battery water pump, and is connected to the motor water-cooling loop through a water valve, which can use the waste heat of the motor to heat the battery or use the battery cooler to independently dissipate heat from the battery, ensuring that the battery is at an appropriate temperature;

[0057] The air-conditioning circuit realizes refrigeration and heating through a compressor, an indoor heat exchanger, etc. Its multi-branch design can stably operate the system and adjust the temperature in the cab. The third branch can input the coolant output by the indoor heat exchanger into the battery cooler, and exchange heat with the coolant in the battery water-cooling circuit to cool down the battery. This system can achieve the coordination of air-conditioning and battery thermal management, improve the energy utilization efficiency, thereby reducing the energy consumption of the thermal management system, and increasing the vehicle's cruising range and air-conditioning comfort.

[0058] Other features and advantages of the present disclosure will be described in the following specification, and, in part, will be obvious from the specification, or will be understood by implementing the present disclosure. The objectives and other advantages of the present disclosure can be achieved and obtained by the structures pointed out in the specification, the claims, and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present disclosure. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0060] Figure 1 Shows a schematic diagram of the system of the present disclosure;

[0061] Figure 2 Shows a schematic diagram of Working Mode 1 of the embodiment of the present disclosure;

[0062] Figure 3 Shows a schematic diagram of Working Mode 2 of the embodiment of the present disclosure;

[0063] Figure 4 Shows a schematic diagram of Working Mode 3 of the embodiment of the present disclosure;

[0064] Figure 5 Shows a schematic diagram of Working Mode 4 of the embodiment of the present disclosure;

[0065] Figure 6 Shows a schematic diagram of Working Mode 5 of the embodiment of the present disclosure;

[0066] Figure 7 Shows a schematic diagram of Working Mode 6 of the embodiment of the present disclosure.

[0067] Reference Numerals in the Drawings:

[0068] 1.1 Radiator; 1.2 Cooling fan; 1.3 Water-cooled condenser three-way valve; 1.4 Motor cooling water pump; 1.5 High-voltage multi-in-one; 1.6 Drive motor; 1.7 Electric drive inlet water temperature sensor; 1.8 Electric drive outlet water temperature sensor; 2.1 Battery pack; 2.2 Battery four-way valve; 2.3 Battery water pump; 2.4 Battery cooler; 2.5 Battery inlet water temperature sensor; 2.6 Battery outlet water temperature sensor; 3.1 Water-cooled condenser; 3.2 Water-cooled condensation outlet water temperature sensor; 3.3 Radiator outlet water temperature sensor; 3.4 Water-cooled condensation water pump; 3.5 Coolant storage pipe; 4.1 Compressor; 4.2 Indoor heat exchanger; 4.3 Air PTC; 4.4 Indoor evaporator; 4.5 Gas-liquid separation tank; 4.6.1 Evaporator electronic expansion valve; 4.6.2 First water-cooled condensation stop valve; 4.6.3 Water-cooled condensation electronic expansion valve; 4.6.4 First battery heating stop valve; 4.6.5 Battery cooling electronic expansion valve; 4.6.6 First battery cooling stop valve; 4.6.7 Second battery cooling stop valve; 4.6.8 Third water-cooled condensation stop valve; 4.6.9 Second battery cooling stop valve; 4.7.1 Compressor outlet temperature sensor; 4.7.2 Indoor heat exchanger outlet pressure sensor; 4.7.3 Evaporator outlet temperature and pressure sensor; 4.7.4 Battery cooler outlet temperature and pressure sensor; 4.7.5 Water-cooled condenser outlet temperature and pressure sensor; 4.7.6 Compressor inlet temperature and pressure sensor. Detailed implementation manners

[0069] To make the objectives, technical solutions, and advantages of the embodiments of the present disclosure clearer, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present disclosure. Apparently, the described embodiments are some but not all of the embodiments of the present disclosure. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present disclosure without creative efforts shall fall within the protection scope of the present disclosure.

[0070] Figure 1 The schematic diagram of the thermal management system architecture according to the present disclosure is shown, which includes:

[0071] 1. The motor water-cooled circuit, including a loop formed by the following components connected in series in sequence:

[0072] The heat dissipation module (including radiator and cooling fan) 1.1, water-cooled condenser three-way valve 1.3, motor cooling water pump 1.4, high-voltage multi-in-one 1.5, drive motor 1.6;

[0073] Wherein, an electric drive inlet water temperature sensor 1.7 is provided at the water inlet of the motor cooling water pump 1.4, and an electric drive outlet water temperature sensor 1.8 is provided at the drive motor 1.6 near the heat dissipation module (including radiator and cooling fan) 1.1.

[0074] 2. Battery water cooling circuit, including the following circuits:

[0075] The battery pack 2.1 has two ends connected in parallel to the input end of the motor cooling water pump 1.4 and the end of the drive motor 1.6 away from the high-voltage all-in-one 1.5 through the battery four-way valve 2.2;

[0076] The first cooling circuit includes the following modules connected in series: a battery cooler 2.4 and a battery water pump 2.3;

[0077] The first cooling circuit is connected in parallel with the battery pack 2 . 1 .

[0078] The battery inlet water temperature sensor 2.5 and the battery outlet water temperature sensor 2.6 are respectively arranged at both ends of the battery pack 2.1.

[0079] 3. A water-cooled condensing circuit, comprising a loop consisting of the following elements connected in series:

[0080] Water-cooled condenser 3.1, heat dissipation module (including radiator, cooling fan) 1.1, water-cooled condensing water pump 3.4;

[0081] It also includes: a coolant storage tank 3.5, which is used to exhaust the coolant circuit and replenish the cooling medium; its output end is connected to the water inlet of the motor cooling water pump 1.4, the battery water pump 2.3, and the water-cooled condensing water pump 3.4.

[0082] The water-cooled condenser outlet water temperature sensor 3.2 and the radiator outlet water temperature sensor 3.3 are respectively arranged at the water outlet of the water-cooled condenser 3.1 and the water outlet of the heat dissipation module.

[0083] 4. Air conditioning circuit:

[0084] It includes the following components connected in series:

[0085] Compressor 4.1, indoor heat exchanger 4.2 (including: indoor heat exchanger 4.2, air PTC 4.3), first water-cooled condensing stop valve 4.6.2, water-cooled condensing electronic expansion valve 4.6.3, water-cooled condenser 3.1;

[0086] Two branches are led out from the output end of the water-cooled condenser 3.1, including:

[0087] The first branch includes a second water-cooled condensation stop valve 4.6.7 and a gas-liquid separation tank 4.5 connected in series, and the output end of the gas-liquid separation tank 4.5 is connected to the input end of the compressor 4.1;

[0088] The output end of the gas-liquid separation tank 4.5 is connected to the input end of the compressor 4.1.

[0089] The second branch includes an evaporator electronic expansion valve 4.6.1 and an indoor evaporator 4.4 connected in series. The output end of the indoor evaporator 4.4 is connected to the input end of the gas-liquid separation tank 4.5.

[0090] In order to make full use of the energy in the air-conditioning circuit, the present disclosure further includes the following circuit arrangements:

[0091] 1) A third branch is led out from the output end of the indoor heat exchanger 4.2, including:

[0092] A first battery heating cut-off valve 4.6.4 and a battery cooling electronic expansion valve 4.6.5 connected in series in sequence; one end of the first battery heating cut-off valve 4.6.4 far from the battery cooling electronic expansion valve 4.6.5 is connected to the output end of the indoor heat exchanger 4.2;

[0093] One end of the battery cooling electronic expansion valve 4.6.5 far from the first battery heating cut-off valve 4.6.4 is connected to one end of the water-cooled condensing electronic expansion valve 4.6.3 far from the water-cooled condenser 3.1 after passing through the battery cooler 2.4 and the second battery cooling cut-off valve 4.6.9.

[0094] 2) A fourth branch is used to input the coolant output from the water-cooled condenser 3.1 into the battery cooler 2.4 for heat exchange with the coolant in the battery water-cooling circuit and then input it into the air-conditioning circuit; it includes:

[0095] A third water-cooled condensing cut-off valve 4.6.8, one end of which is connected to one end of the water-cooled condenser 3.1 far from the water-cooled condensing electronic expansion valve 4.6.3, and the other end is connected to one end of the battery cooling electronic expansion valve 4.6.5 far from the battery cooler 2.4;

[0096] A first battery cooling cut-off valve 4.6.6, one end of which is connected to the connection point of the battery cooler 2.4 and the second battery cooling cut-off valve 4.6.9, and the other end is connected to the input end of the connection gas-liquid separation tank 4.5.

[0097] Specifically, it further includes:

[0098] A compressor outlet temperature sensor 4.7.1 for monitoring the refrigerant temperature at the compressor outlet;

[0099] An indoor heat exchanger outlet pressure sensor 4.7.2 for monitoring the refrigerant pressure at the indoor heat exchanger outlet;

[0100] An evaporator outlet temperature and pressure sensor 4.7.3 for monitoring the refrigerant temperature and pressure at the evaporator outlet;

[0101] A battery cooler outlet temperature and pressure sensor 4.7.4 for monitoring the refrigerant temperature and pressure at the battery cooler outlet;

[0102] Water-cooled condenser outlet temperature and pressure sensor 4.7.5, used to monitor the refrigerant temperature and pressure at the water-cooled condenser outlet;

[0103] Compressor inlet temperature and pressure sensor 4.7.6 is used to monitor the refrigerant temperature and pressure at the compressor inlet.

[0104] The following are specific examples of the present disclosure:

[0105] The disclosed system architecture can realize the following working modes:

[0106] Mode 1: Motor cooling circuit:

[0107] When only the motor circuit of the thermal management system has cooling requirements: that is, the logic judgment 1.6 motor (TM) actively requests cooling or the body temperature exceeds the target temperature (80°C) or the 1.5 high pressure all-in-one (PDC) temperature exceeds the target temperature (65°C) or the 1.7 electric drive inlet water temperature and the 1.8 electric drive outlet water temperature exceed the target temperature (60°C), the low temperature cooling circuit works:

[0108] At this time, the flow direction of 1.3 water-cooled condensing three-way valve is as follows Figure 2 As shown, 1.2 cooling fan and 1.4 motor cooling water pump comprehensively calculate the change value of the above judgment conditions within unit time (5s) and linearly output the cooling fan and water pump speeds.

[0109] Mode 2: Passive battery cooling circuit:

[0110] When only the battery circuit of the thermal management system has a passive cooling requirement: that is, the logic judges that the 2.1 battery (BMS) has a cooling requirement, and the ambient temperature is 5°C lower than the 2.5 battery inlet water temperature sensor or 5°C lower than the 2.6 battery outlet water temperature sensor; the battery passive cooling circuit works:

[0111] At this time, the flow direction of 1.3 water-cooled condensing three-way valve is as follows Figure 3 As shown, the flow direction of the battery four-way valve 2.2 is as shown in the figure above, 1.2 cooling fan and 2.3 battery cooling water pump comprehensively calculate the change value of the above judgment conditions within unit time (5s) and linearly output the cooling fan and water pump speed.

[0112] Mode 3: Battery circuit recycles waste heat from motor circuit:

[0113] When the thermal management system only has a heating demand for the battery circuit and a cooling demand for the motor circuit: that is, the logic judgment 2.1 The battery (BMS) has a heating demand, and 45℃>1.8 The electric drive outlet water temperature is >2.5 The battery inlet water temperature sensor is 5℃ or 2.6 The battery outlet water temperature sensor is 5℃, the battery recovery motor waste heat circuit works:

[0114] 2.2 The flow direction of the battery four-way valve is as follows Figure 4As shown, the 1.4 cooling fan and the 2.3 battery cooling water pump comprehensively calculate the change value of the above judgment conditions and linearly output the water pump speed.

[0115] Mode 4: Motor circuit cooling, battery circuit active cooling, cab temperature reduction:

[0116] When the motor circuit of the thermal management system has a cooling demand, the battery circuit has an active cooling demand, and the cab has a refrigeration demand: that is, the logical judgment is that 1.6 the motor (TM) actively requests cooling or the body temperature exceeds the target temperature (80 °C) or 1.5 the high-voltage multi-in-one (PDC) temperature exceeds the target temperature (65 °C) or 1.7 the inlet water temperature of the electric drive, 1.8 the outlet water temperature of the electric drive exceeds the target temperature (60 °C); & 2.1 the battery (BMS) has a cooling demand, and the ambient temperature is 5 °C higher than the 2.5 battery inlet water temperature sensor or the 2.6 battery outlet water temperature sensor; and when the cab requires refrigeration, the ambient temperature is higher than the cab temperature:

[0117] ① The flow direction of the 1.3 water-cooled condensation three-way valve in the motor circuit is as shown Figure 5 As shown, the 1.2 cooling fan and the 1.4 motor cooling water pump comprehensively calculate the change value of the above judgment conditions within a unit time (5 s) and linearly output the cooling fan and water pump speeds;

[0118] ② The flow direction of the 2.2 battery four-way valve in the battery circuit is closed as shown in the above figure. The 1.4 cooling fan and the 2.3 battery cooling water pump comprehensively calculate the change value of the above judgment conditions and linearly output the water pump speed;

[0119] ③ The 3.4 water-cooled condensation water pump and the 1.4 cooling fan in the water-cooled condensation circuit linearly output the cooling fan and water pump speeds based on the 3.2 water-cooled condensation outlet water temperature and the 3.3 radiator outlet water temperature;

[0120] ④ Air conditioning circuit 4.6.4 The first battery heating stop valve is disconnected, 4.6.7 The second battery cooling stop valve is disconnected, 4.6.9 The second battery cooling stop valve is disconnected, 4.6.3 The water-cooled condensing electronic expansion valve is opened 100%, 4.6.1 The evaporator electronic expansion valve opening is calculated based on the evaporator outlet refrigerant temperature and pressure table lookup at 4.7.3 and PI control is performed with a superheat target of 8°C, 4.6.2 The water-cooled condensing stop valve is closed, 4.6.5 The battery cooling electronic expansion valve opening is calculated based on the battery cooling outlet refrigerant temperature and pressure at 4.7.4. The pressure table is used for calculation and PI control is performed with a superheat target of 8°C. 4.6.6 The first battery cooling stop valve is closed. 4.6.8 The third water-cooled condensing stop valve is closed. 4.1 Compressor speed control is based on 4.7.5 Water-cooled condensing outlet refrigerant temperature and pressure table calculation and PI control is performed with a supercooling target of 10°C. The speed is limited by 4.7.2 Indoor heat exchanger outlet pressure and 4.7.6 Compressor inlet temperature and pressure. 1.4 The cooling fan outputs speed linearly with the change value of 4.7.2 Indoor heat exchanger outlet pressure.

[0121] Mode 5: Motor circuit cooling, battery circuit active heating, cab heating:

[0122] When the thermal management system motor circuit has cooling requirements, the battery circuit has active heating requirements, and the cab has heating requirements: that is, the logic judgment 1.6 motor (TM) actively requests cooling or the body temperature exceeds the target temperature (80°C) or the 1.5 high-voltage all-in-one (PDC) temperature exceeds the target temperature (65°C) or the 1.7 electric drive inlet water temperature and the 1.8 electric drive outlet water temperature exceed the target temperature (60°C); & 2.1 battery (BMS) has heating requirements, and the ambient temperature is lower than the 2.5 battery inlet water temperature sensor or the 2.6 battery outlet water temperature sensor; & the ambient temperature is lower than the cab temperature when the cab needs to be heated, thermal management mode five works:

[0123] ① Motor circuit 1.3 Water cooling condensation three-way valve flow direction as follows Figure 6 As shown, 2.2 The flow direction of the battery four-way valve is as shown in the figure above, 1.4 The motor cooling water pump comprehensively calculates the change value of the above judgment conditions within a unit time (5s) and linearly outputs the water pump speed;

[0124] ② Battery circuit 2.2 The flow direction of the battery four-way valve is closed as shown in the figure above, 2.3 The battery cooling water pump comprehensively calculates the change value of the above judgment conditions and linearly outputs the water pump speed;

[0125] ③ The water-cooled condensing circuit 3.4 water-cooled condensing water pump outputs the cooling fan and water pump speed linearly based on the water temperature at the outlet of the water-cooled condensing 3.2 and the water temperature at the outlet of the electric drive 1.8;

[0126] ④ Air conditioning circuit 4.6.1 Evaporator electronic expansion valve is closed, 4.6.2 Stop valve is disconnected, 4.6.6 Stop valve is disconnected, 4.6.8 Stop valve is disconnected, 4.6.4 Stop valve is energized, 4.6.7 Stop valve is energized, 4.6.9 Stop valve is energized, 4.6.5 Battery cooler electronic expansion valve opening is 100%, 4.6.3 Water-cooled condensing electronic expansion valve opening is calculated based on 4.7.5 Water-cooled condensing outlet refrigerant temperature and pressure table lookup with superheat target of 8°C for PI control, 4.1 Compressor speed 4.7.1 Compressor outlet temperature, 4.7.2 Indoor heat exchanger outlet pressure and 4.7.6 Compressor inlet temperature and pressure are used to limit the speed.

[0127] Mode 6: Motor circuit cooling, battery circuit active cooling, cab heating:

[0128] When the thermal management system motor circuit has cooling requirements, the battery circuit has active cooling requirements, and the cab has heating requirements: that is, the logic judgment 1.6 motor (TM) actively requests cooling or the body temperature exceeds the target temperature (80°C) or the 1.5 high-voltage all-in-one (PDC) temperature exceeds the target temperature (65°C) or the 1.7 electric drive inlet water temperature and the 1.8 electric drive outlet water temperature exceed the target temperature (60°C); && 2.1 battery (BMS) has cooling requirements, and the ambient temperature is higher than the 2.5 battery inlet water temperature sensor or the 2.6 battery outlet water temperature sensor by 5°C; & When the ambient temperature in the cab is required to be heated, it is lower than the cab temperature, and thermal management mode six works.

[0129] ①1.3 Flow direction of water-cooled condensing three-way valve Figure 7 As shown, 1.2 cooling fan and 1.4 motor cooling water pump comprehensively calculate the change value of the above judgment conditions within unit time (5s) and linearly output the cooling fan and water pump speed;

[0130] ② Battery circuit 2.2 The flow direction of the battery four-way valve is closed as shown in the figure above, 2.3 The battery cooling water pump comprehensively calculates the change value of the above judgment conditions and linearly outputs the water pump speed;

[0131] ③ The water-cooled condensing circuit 3.4 water-cooled condensing water pump outputs the cooling fan and water pump speed linearly based on the water temperature at the outlet of the water-cooled condensing 3.2 and the water temperature at the outlet of the electric drive 1.8;

[0132] ④ Air conditioning circuit 4.6.1 Evaporator electronic expansion valve is closed, 4.6.2 Stop valve is energized, 4.6.6 Stop valve is energized, 4.6.8 Stop valve is disconnected, 4.6.4 Stop valve is energized, 4.6.7 Stop valve is energized, 4.6.9 Stop valve is disconnected, 4.6.5 Battery cooler electronic expansion valve opening is calculated based on 4.7.4 Battery cooling outlet refrigerant temperature and pressure table lookup with superheat target of 8°C for PI control, 4.6.3 Water-cooled condensing electronic expansion valve opening is calculated based on 4.7.5 Water-cooled condensing outlet refrigerant temperature and pressure table lookup with superheat target of 8°C for PI control, 4.1 Compressor speed 4.7.1 Compressor outlet temperature, 4.7.2 Indoor heat exchanger outlet pressure and 4.7.6 Compressor inlet temperature and pressure are used to limit the speed.

[0133] Based on the above main mode, it can be decomposed into multiple sub-modes, and the control logic remains consistent with the above.

[0134] Component function description:

[0135] 1.1 Radiator: used for cooling motors, batteries and air conditioning systems;

[0136] 1.2 Cooling fan: used to increase the air volume passing through the radiator;

[0137] 1.3 Three-way valve of water-cooled condenser: used to change the flow direction of cooling medium flowing through the radiator;

[0138] 1.4 Motor cooling water pump: used to provide pump energy to the motor circuit cooling medium;

[0139] 1.5 High voltage all-in-one: including charger, voltage reducer, distribution box and other high voltage components integration;

[0140] 1.6 Driving motor: provides power for driving the vehicle;

[0141] 1.7 Electric drive inlet water temperature sensor: monitors the inlet cooling medium temperature of the drive motor;

[0142] 1.8 Electric drive outlet water temperature sensor: monitors the outlet cooling medium temperature of the drive motor;

[0143] 2.1 Battery pack: provides power for the entire vehicle;

[0144] 2.2 Battery four-way valve: changes the flow direction of the battery circuit cooling medium;

[0145] 2.3 Battery water pump: used to provide pump energy to the battery circuit cooling medium;

[0146] 2.4 Battery cooler: used to cool or heat the cooling medium of the battery circuit;

[0147] 2.5 Battery inlet water temperature sensor: monitors the temperature of the battery inlet cooling medium;

[0148] 2.6 Battery outlet water temperature sensor: Monitors the temperature of the cooling medium at the battery outlet.

[0149] 3.1 Water-cooled condenser: Used to cool the refrigerant in the air-conditioning system.

[0150] 3.2 Water-cooled condenser outlet water temperature sensor: Monitors the temperature of the cooling medium at the outlet of the water-cooled condenser.

[0151] 3.3 Radiator outlet water temperature sensor: Monitors the temperature of the cooling medium at the radiator outlet.

[0152] 3.4 Water-cooled condenser water pump: Used to provide pump energy for the cooling medium in the water-cooled condenser loop.

[0153] 3.5 Coolant storage pipe: Used to exhaust air from the coolant loop and supplement the cooling medium.

[0154] 4.1 Compressor: Used to provide compression energy for the refrigerant in the air-conditioning system.

[0155] 4.2 Indoor heat exchanger: Used to provide heat and heating for the cab.

[0156] 4.3 Air PTC: Used to heat air to provide heat and heating for the cab.

[0157] 4.4 Indoor evaporator: Used to absorb heat from the cab and cool it.

[0158] 4.5 Gas-liquid separator: Used to separate the inadequately expanded liquid refrigerant in the air-conditioning system.

[0159] 4.6.1 Evaporator electronic expansion valve: Used to expand the flowing refrigerant, change the phase state of the refrigerant, and thus absorb heat through phase change.

[0160] 4.6.2 First water-cooled condenser shut-off valve: Used to cut off the refrigerant flowing to the water-cooled condenser, and heat the battery or recover the waste heat of the battery in the heat pump mode.

[0161] 4.6.3 Water-cooled condenser electronic expansion valve: Used to expand the flowing refrigerant, change the phase state of the refrigerant, and thus absorb heat through phase change.

[0162] 4.6.4 First battery heating shut-off valve: Used to cut off the refrigerant flowing to the battery cooler, and cool the battery or when the battery has no demand in the refrigeration mode.

[0163] 4.6.5 Battery cooling electronic expansion valve: Used to expand the flowing refrigerant, change the phase state of the refrigerant, and thus absorb heat through phase change.

[0164] 4.6.6 First battery cooling shut-off valve: Used to cut off the refrigerant flowing to the gas-liquid separator, and recover the waste heat of the battery or when the battery has no demand in the heat pump mode.

[0165] 4.6.7 Second battery cooling shut-off valve: Used to cut off the refrigerant flowing to the gas-liquid separation tank, cooling the battery or the cab in the refrigeration mode;

[0166] 4.6.8 Third water-cooled condenser shut-off valve: Used to cut off the water-cooled condensed refrigerant flowing to the battery cooler, heating the battery in the heat pump mode or recovering the waste heat of the battery in the heat pump mode or when the battery has no demand;

[0167] 4.6.9 Second battery cooling shut-off valve: Used to cut off the refrigerant of the battery cooler flowing to the water-cooled condensation, cooling the battery in the refrigeration mode or recovering the waste heat of the battery in the heat pump mode or when the battery has no demand;

[0168] 4.7.1 Compressor outlet temperature sensor: Monitors the refrigerant temperature at the compressor outlet;

[0169] 4.7.2 Indoor heat exchanger outlet pressure sensor: Monitors the refrigerant pressure at the indoor heat exchanger outlet;

[0170] 4.7.3 Evaporator outlet temperature and pressure sensor: Monitors the refrigerant temperature and pressure at the evaporator outlet;

[0171] 4.7.4 Battery cooler outlet temperature and pressure sensor: Monitors the refrigerant temperature and pressure at the battery cooler outlet;

[0172] 4.7.5 Water-cooled condenser outlet temperature and pressure sensor: Monitors the refrigerant temperature and pressure at the water-cooled condensation outlet;

[0173] 4.7.6 Compressor inlet temperature and pressure sensor: Monitors the refrigerant temperature and pressure at the compressor inlet.

[0174] Based on the method of the present disclosure, embodiments of the present disclosure also provide a control method applied to the above system, which includes:

[0175] When only the motor has a cooling demand in the thermal management system, turn on the radiator 1.1 and the motor cooling water pump 1.4;

[0176] When only the battery has a passive cooling demand in the thermal management system, turn on the radiator 1.1 and the battery water pump 2.3, and conduct the battery four-way valve 2.2 so that the coolant output by the radiator 1.1 flows through the battery pack 2.1 and then is transmitted back to the input end of the radiator 1.1.

[0177] Although the present disclosure has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: They can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present disclosure.

Claims

1. A thermal management system for an electric vehicle, comprising a motor water cooling circuit, a battery water cooling circuit, an air conditioning circuit and a third branch; characterized in that: The motor water cooling circuit includes a radiator (1.1), a motor cooling water pump (1.4) and a drive motor (1.6) connected in series in sequence; The battery water cooling circuit includes a battery pack (2.1) and a first cooling line for cooling the battery pack (2.1); the first cooling line includes a battery cooler (2.4) and a battery water pump (2.3) connected in series; the battery pack (2.1) is connected in parallel with both ends of the radiator (1.1) through a water valve; The air conditioning circuit includes: a compressor (4.1), an indoor heat exchanger (4.2), a first water-cooled condensation stop valve (4.6.2), a water-cooled condensation electronic expansion valve (4.6.3) and a water-cooled condenser (3.1) connected in series in sequence; a first branch and a second branch are led out from one end of the water-cooled condenser (3.1) far away from the water-cooled condensation electronic expansion valve (4.6.3); wherein, the first branch is used for inputting the coolant back to the compressor (4.1), and the second branch is used for inputting the coolant output from the water-cooled condenser (3.1) to the indoor evaporator (4.4) and then returning to the compressor (4.1); The third branch is used for inputting the coolant output from the indoor heat exchanger (4.2) into the battery cooler (2.4) to exchange heat with the coolant in the battery water cooling circuit and then inputting it back into the air conditioning circuit.

2. The thermal management system of an electric vehicle according to claim 1, characterized in that, The first branch includes a second water-cooled condensation stop valve (4.6.7) and a gas-liquid separation tank (4.5) connected in series, and the output end of the gas-liquid separation tank (4.5) is connected to the input end of the compressor (4.1); The second branch includes an evaporator electronic expansion valve (4.6.1) and an indoor evaporator (4.4) connected in series, and the output end of the indoor evaporator (4.4) is connected to the input end of the gas-liquid separation tank (4.5).

3. The thermal management system of an electric vehicle according to claim 2, characterized in that, The third branch includes: A first battery heating stop valve (4.6.4) and a battery cooling electronic expansion valve (4.6.5) connected in series in sequence; One end of the first battery heating stop valve (4.6.4) far away from the battery cooling electronic expansion valve (4.6.5) is connected to the output end of the indoor heat exchanger (4.2); One end of the battery cooling electronic expansion valve (4.6.5) far away from the first battery heating stop valve (4.6.4) is connected to one end of the water-cooled condensation electronic expansion valve (4.6.3) far away from the water-cooled condenser (3.1) after passing through the battery cooler (2.4).

4. The thermal management system of an electric vehicle according to claim 3, characterized in that, It further includes a fourth branch, which is used for inputting the coolant output from the water-cooled condenser (3.1) into the battery cooler (2.4) to exchange heat with the coolant in the battery water cooling circuit and then inputting it back into the air conditioning circuit, and it includes: A third water-cooled condensation stop valve (4.6.8), one end of which is connected to one end of the water-cooled condenser (3.1) far away from the water-cooled condensation electronic expansion valve (4.6.3), and the other end is connected to one end of the battery cooling electronic expansion valve (4.6.5) far away from the battery cooler (2.4); The first battery cooling cut-off valve (4.6.6), one end of which is connected to the end of the battery cooler (2.4) away from the third water-cooled condensation cut-off valve (4.6.8), and the other end is connected to the input end of the gas-liquid separation tank (4.5).

5. The thermal management system of an electric vehicle according to claim 1, characterized in that One end of the water-cooled condenser (3.1) is also connected to one end of the radiator (1.1) after passing through the water-cooled condensation water pump (3.4); The other end of the water-cooled condenser (3.1) is connected to the other end of the radiator (1.1).

6. The thermal management system of an electric vehicle according to claim 5, characterized in that, The motor water-cooled circuit further includes: A water-cooled condensation three-way valve (1.3), two ports of which are connected to the radiator (1.1) and the motor cooling water pump (1.4), and the third port is connected to the water inlet of the water-cooled condensation water pump (3.4).

7. A control method for a thermal management system of an electric vehicle according to claim 1, characterized in that, Including: When the battery in the thermal management system has a passive cooling requirement: Open the radiator (1.1) and the battery water pump (2.3), and conduct the water valve so that the coolant output from the radiator (1.1) flows through the battery pack (2.1) and then is transmitted back to the input end of the radiator (1.1).

8. The control method according to claim 7, wherein When the battery in the thermal management system has a passive heating requirement and the motor has a passive cooling requirement: Open the motor cooling water pump (1.4) and the battery water pump (2.3); Conduct the water valve so that the coolant passing through the motor flows through the battery pack (2.1) and then is transmitted back to the water inlet of the motor cooling water pump (1.4).

9. The control method according to claim 7, characterized in that When the battery in the thermal management system has an active cooling requirement and the air-conditioning circuit has a refrigeration requirement: Open the battery water pump (2.3) and the battery cooler (2.4); Open the compressor (4.1), the first water-cooled condensation cut-off valve (4.6.2), and the indoor evaporator (4.4); Use the fourth branch to input the coolant output from the water-cooled condenser (3.1) into the battery cooler (2.4) for heat exchange with the coolant in the battery water-cooled circuit, and then input it back into the air-conditioning circuit.

10. A thermal management system for an electric vehicle according to claim 7, wherein When the battery circuit in the thermal management system has an active heating requirement and the air-conditioning circuit has a heating requirement: Open the battery water pump (2.3) and the battery cooler (2.4); Open the compressor (4.1) and the indoor heat exchanger (4.2); And use the third branch to input the coolant output from the indoor heat exchanger (4.2) into the battery cooler (2.4), for heat exchange with the coolant in the battery water-cooled circuit, and then input it to the end of the water-cooled condensation electronic expansion valve (4.6.3) away from the water-cooled condenser (3.1).

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